Unleashed guest portal problem since clients were redirected to management IP of the AP.

I have R600 unleashed with firmware version R600_200.1.9.12.62.. The unit was configured with multiple SSID in multiple vlan environment. for example guest SSID was configured with vlan10 but the result when guest users access the internet it redirects them to the management IP of the AP.. when I used vlan1 for guest it is working fine, clients can view the guest portal terms and services. what could be the issue?